title: Spironolactone does not prevent acute mountain sickness: a prospective, double-blind, randomized, placebo-controlled trial by SPACE Trial Group (spironolactone and acetazolamide trial in the prevention of acute mountain sickness group).
abstract: OBJECTIVE
  Over the last 20 years a number of small trials have reported that spironolactone effectively prevents acute mountain sickness (AMS), but to date there have been no large randomized trials investigating the efficacy of spironolactone in prevention of AMS. Hence, a prospective, double-blind, randomized, placebo-controlled trial was conducted to evaluate the efficacy of spironolactone in the prevention of AMS.
  
  
  METHODS
  Participants were sampled from a diverse population of western trekkers recruited at 4300 m on the Mount Everest base camp approach (Nepal side) en route to the study endpoint at 5000 m. Three hundred and eleven healthy trekkers were enrolled, and 251 completed the trial from October to November 2007. Participants were randomly assigned to receive at least 3 doses of spironolactone 50 mg BID, acetazolamide 250 mg BID, or visually matched placebo. A Lake Louise AMS Score of 3 or more, together with the presence of headache and 1 other symptom, was used to evaluate the incidence and severity of AMS. Secondary outcome measures were blood oxygen content and the incidence and severity of high altitude headache (HAH).
  
  
  RESULTS
  Acetazolamide was more effective than spironolactone in preventing AMS (OR = 0.28, 95% CI 0.12-0.60, p < 0.01). Spironolactone was not significantly different from placebo in the prevention of AMS. AMS incidence for placebo was 20.3%, acetazolamide 10.5%, and spironolactone 29.4%. Oxygen saturation was also significantly increased in the acetazolamide group (83% ± 0.04) vs spironolactone group (80% ± 0.05, p < 0.01).
  
  
  CONCLUSIONS
  Spironolactone (50 mg BID) was ineffective in comparison to acetazolamide (250 mg BID) in the prevention of AMS in partially acclimatized western trekkers ascending to 5000 m in the Nepali Himalaya.
authors.affiliation: Nepal International Clinic, Kathmandu, Nepal.
authors.forename: Buddha
authors.initials: B
authors.lastname: Basnyat
authors.forename: Peter S
authors.initials: PS
authors.lastname: Holck
authors.forename: Matiram
authors.initials: M
authors.lastname: Pun
authors.forename: Stephen
authors.initials: S
authors.lastname: Halverson
authors.forename: Piotr
authors.initials: P
authors.lastname: Szawarski
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Gertsch
authors.forename: Mike
authors.initials: M
authors.lastname: Steif
authors.forename: Skip
authors.initials: S
authors.lastname: Powell
authors.forename: Subhash
authors.initials: S
authors.lastname: Khanal
authors.forename: Anip
authors.initials: A
authors.lastname: Joshi
authors.forename: Ravi
authors.initials: R
authors.lastname: Shankar
authors.forename: Jamie
authors.initials: J
authors.lastname: Karambay
authors.forename: Hattie D
authors.initials: HD
authors.lastname: Alexander
authors.forename: Allyson
authors.initials: A
authors.lastname: Stone
authors.forename: Candice
authors.initials: C
authors.lastname: Morrissey
authors.forename: Beth H
authors.initials: BH
authors.lastname: Thompson
authors.forename: Jeremy
authors.initials: J
authors.lastname: Farrar
mesh_terms: D000086:Acetazolamide / Q000008:administration & dosage; D000328:Adult; D000532:Altitude Sickness / Q000453:epidemiology / Q000517:prevention & control*; D004311:Double-Blind Method; D005260:Female; D006261:Headache / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D008297:Male; D009051:Mountaineering; D009390:Nepal / Q000453:epidemiology; D010100:Oxygen / Q000097:blood; D011446:Prospective Studies; D013148:Spironolactone / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D013148:Spironolactone; D000086:Acetazolamide; D010100:Oxygen